(1) In the case of any plan of life insurance that provides for future premium determination, the amounts of which are to be determined by the insurance company based on then-present estimates of future experience, or in the case of any plan of life insurance or annuity that is of such a nature that the minimum reserves cannot be determined by the methods described in sections 10-7-310, 10-7-310.5, and 10-7-313, the reserves that are held under any such plan must:
(a) Be appropriate in relation to the benefits and the pattern of premiums for that plan; and
(b) Be computed by a method that is consistent with the principles of this part 3, as such appropriateness and method is determined by rules promulgated by the commissioner.